„Last year a Dutch animal breeding centre sent me two chimpanzees as a gift. I killed one and cut its heart out. The other wept bitterly and was inconsolable. The sad chimp has long since happily mated again and lives with lots of other animals on a pleasant game farm near Villiersdorp. I vowed never again to experiment with such sensitive creatures, but the memory of that weeping chimp has remained with me. It was taken for granted, of course, that he was weeping for his mate but I've since had some thoughts on the subject which made me wonder whether perhaps he was weeping for the human race. The idea is not as silly as it sounds. In our doings there is much to weep over and even a chimpanzee would never behave in some of the contradictory ways we think of as normal.“
— Christiaan Barnard
The Best Medicine (Cape Town: Tafelberg Publishers, 1979), p. 38.